Rice Response to Herbicides under Lowland and Irrigation Ecologies of Sudan Savanna Ecological Zone of Nigeria

Abstract

A field trial was conducted in 2008 growing season in lowland and irrigation rice ecologies to study the effect of various herbicide combinations on weed characteristics, crop growth and the corresponding grain yield and financial return of rice cultivation. The treatments were Butachlor, Propanil and 2, 4 - D applied at 3 levels in various combinations with or without supplementary hoe weeding. The trials were laid out by using randomized complete block design. The data collected were subjected to analysis of variance were significant the means were separated using Duncan multiple range test. The results indicated that the use of all the herbicides lowered the weed cover score and weed dry weight compared to weedy check. Application of Butachlor at the rate of 2.25 kg a.i. ha -1 followed by Propanil and 2, 4 - D mixture at the rate of 2.52 and 1.44 kg a.i. ha-1 , respectively produced higher crop vigor and number of tillers per plant and the highest grain yield per hectare. Gross margin and cost benefit analysis were employed to determine the profitability of each of the control methods. The same treatment that produced higher grain yield also gave the highest gross margin and Cost- benefit ratio over manual hoe weeding and as such considered the best treatment for rice production in both ecologies.